From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 28 Jan 2004 20:00:58 +0000 (GMT) Received: from nevyn.them.org ([IPv6:::ffff:66.93.172.17]:36256 "EHLO nevyn.them.org") by linux-mips.org with ESMTP id ; Wed, 28 Jan 2004 20:00:57 +0000 Received: from drow by nevyn.them.org with local (Exim 4.30 #1 (Debian)) id 1Alvrg-00048J-1L; Wed, 28 Jan 2004 15:00:44 -0500 Date: Wed, 28 Jan 2004 15:00:44 -0500 From: Daniel Jacobowitz To: Jun Sun Cc: Rajesh Palani , linux-mips@linux-mips.org Subject: Re: SoftFloat implementation for MIPS in GCC Message-ID: <20040128200044.GA15794@nevyn.them.org> References: <20040128192636.32578.qmail@web21603.mail.yahoo.com> <20040128193355.GA14318@nevyn.them.org> <20040128115312.B6210@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040128115312.B6210@mvista.com> User-Agent: Mutt/1.5.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 4179 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: dan@debian.org Precedence: bulk X-list: linux-mips On Wed, Jan 28, 2004 at 11:53:12AM -0800, Jun Sun wrote: > On Wed, Jan 28, 2004 at 02:33:55PM -0500, Daniel Jacobowitz wrote: > > On Wed, Jan 28, 2004 at 11:26:36AM -0800, Rajesh Palani wrote: > > > Hi, > > > > > > We are using a gcc 2.96 20000731 (Red Hat Linux 7.1 2.96-99.1) GCC cross-compiler with -msoftfloat to use software floating point routines. > > > > > > When we profied an application using the Linux Trace Toolkit, we observed that there were a lot of CpU (Co-processor unusable) exceptions. Some of the floating point routines ( eg. __floatdidf) expect values to be passed in floating point registers and take FP exceptions even though the application has been built with -msoftfloat. Is this a general MIPS/GCC issue? What is the status of softfloat for MIPS in GCC? > > > > Try a more recent compiler, that one is ancient. If you configure > > correctly, you should get no references to the floating point registers > > at all. > > > > If glibc is not compiled with -msoftfloat, I think you will get a few > FPU exceptions from glibc no matter how apps are compiled. > > Actually, will it be a problem if glibc and apps are compiled differently > (such as in longjump, sig handling area)? Yes, that will be a problem. Nothing that takes or returns a floating point value will work either. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer